This invention relates generally to espresso coffee making and more particularly to a system and method for providing and serving, fully automatically, such coffee beverages as cafe latte, cappuccino, and the like, from roasted whole beans and fresh, cold milk.
The practice of brewing espresso and making and serving steamed or foamed milk inclusive beverages such as lattes or cappuccinos is a well developed field and now includes fully automatic machines which provide a choice of beans, e.g. "regular" or "decaf", and integrally housed, refrigerated milk. In the most compact and hygienically excellent such machines, the milk is refrigerated within the console of the integral structure until it is drawn to the aeration and steaming apparatus and delivered to the serving cup in timed cooperation with the brewing process. The milk path is then cleared of residual milk and steam cleaned whereby all milk is either aerated and served or refrigerated after each drink preparation cycle.
A machine which successfully achieves all these functions with hygienic excellence is thoroughly described in U.S. Pat. No. 5,207,148 issued May 4, 1993, and entitled "Automated Milk, Inclusive Coffee Apparatus".
In the system described in the referenced patent, milk is drawn from an internal, refrigerated single source by a steam driven venturi and then forced through a vortex chamber for aeration before being delivered to the beverage cup. The timing of the steam valving being such that after the milk valve between the milk supply and the venturi throat is closed, the steam flow briefly continues to cleanse the venturi, vortex chamber, and all delivery piping to the serving cup. In practice, the valving of the refrigerated milk into the steam heated venturi throat and the calibration and adjustments to the several parameters of the venturi and vortex chambers have been complex and are exceedingly interdependent upon each other thusly constituting a delicate and relatively critical maintenance operation requiring special skills.
Accordingly, it is an object of the present invention to provide an automated, hygienically safe milk inclusive espresso system and method, which does not depend on steam driven venturi technology, for drawing milk from an internal refrigerated source, aerating it, heating it, and delivering it to the beverage cup.
It is another object to provide in such apparatus a milk delivery system, which is rugged, reliable, and inexpensive to manufacture and maintain.
It is another object to provide such milk aeration, heating, and delivery with an exceedingly high degree of versatility, with respect to such parameters as milk selection, e.g. low fat versus non fat, latte versus cappuccino, degree of milk aeration, temperature of the delivered aerated milk, and its quantity.
It is another object to provide such apparatus which in addition to achieving hygienic pumping of the milk with each serving cycle, may be programmed to provide automatically a periodic complete system cleaning process.
It is another object to provide such a combination in which the adjustability of the various operating parameters of the several components such as air flow, fluid flow, steam flow, and timing are essentially independent of each other.